Determination of the Thermal Parameters of Geopolymers Modified with Iron Powder

The paper presents the results of research concerning the influence of a metallic micromaterial on the thermal conductivity lambda, specific heat Cp, and thermal diffusivity a of modified geopolymers. Iron oxide in the form of powder with an average granulation of 10 mu m was used as the geopolymer-modifying material. The research concerned geopolymer composite samples with metakaolin (activated with potassium silicate) and the addition of iron in amounts ranging from 0.5% to 2.5% in relation to the weight of the metakaolin. Additionally, the samples were modified with sand and fireclay in two different amounts-1:1 and 1:1.2 in relation to the metakaolin. The addition of fireclay caused a decrease in the thermal conductivity of the composites by 30% when compared to the samples with the addition of sand. The lowest value of the thermal conductivity coefficient lambda was obtained for the geopolymer with metakaolin and fireclay. When the ratio of these components in the composite was 1:1, the value of thermal conductivity was equal to 0.6413 W/(m center dot K), while in the case of their ratio being 1:1.2, it was equal to 0.6456 W/(m center dot K). In the samples containing fireclay, no significant influence of the added iron on the values of thermal conductivity was noticed. In the case of the geopolymer with sand, the effect was noticeable, and it was most visible in the samples containing metakaolin and sand in the ratio of 1:1.2. It was noticed that with an increase in the addition of Fe, the thermal conductivity of the composite increased.

Automated summary

This paper presents the research results on the influence of metallic micromaterial on the thermal conductivity, specific heat, and thermal diffusivity of modified geopolymers. The addition of fireclay can decrease the thermal conductivity of the composites, while the added iron has no significant influence on the thermal conductivity in the samples containing fireclay.